Adwords free Coupons or vouchers, are readily available to you through different sources in different denominations.
Google distributes it through agencies, blogs, books and even directly. Many qualified companies and individuals receive it in tons. I myself get vouchers from google to be given to new advertisers. These vouchers mostly of Rs2500 and Rs5000 (USD100), are supposed to be distributed to New Advertisers.
However, lure of free has attracted many quacks who are just using them to run free PPC by creating new accounts. Last year many advertisers were banned because their account was identified as such.
Many people call me just to get free vouchers. These people typically won't talk about anything else, not even about their business! There are agencies which have become Voucher Traders and few offered me a deal too.
Well, I use my vouchers for my own clients who would like to start a new account for their new business or even new clients who are also willing to pay something. I ignore People who are writing or calling me just for vouchers, because most of them I feel are not genuine advertisers, and so are not worth giving attention.
The greatest problem is that Rs2500 vouchers have become so common that some of them you would find in your nearby dustbin, just go and give it a try, and it is a fallacy that only Qualified individuals and companies can give Rs5000 vouchers. I have learnt, Google directly gives them to anybody they wish to, if she bothers to call their toll free number and asks for it, and answers some questions to their satisfaction that they are intending to spend a decent amount per day.
Reality is that most such accounts vanishes after voucher amount gets exhausted and in many cases reincarnated as a New Business again, till the website and account holder gets banned by google.
Problem lies in identifying the genuine new users. I personally feel, they should be given to an account having passed certain amount of spent. Google can do it easily, by imposing the condition that although vouchers would be credited at the time of creation of account, it would be effective only when it passes certain amount spent threshold. It might be an effective check against all these voucher scams.
Free vouchers which are free for apparent (or imposter?) newbie actually are actually additional cost to genuine advertisers. It inflates the bidding, and puts extra burden on people who are paying for clicks by forcing them compete with people who are just fiddling with bid. Increasing the number of players in the auction is beneficial for Google. It earns extra by allowing new advertisers into the auction free of cost, by creating pressure on people who actually pays.